I have a home ventilation switch that I would like to wire a timer to. This switch is located in my upstairs hallway, and when flipped it turns on the furnace fan blower and the main bathroom exhaust fan. However, when I look in the junction box, it's unlike anything I've ever seen.
The switch has four terminals (plus ground), with a standard high voltage wire connected to one side, and a pair of low voltage wires connected to the other side. While I can't trace it through the wall, there is a similar red-sleeved low-voltage wire connected to the control panel on my furnace blower, which I assume is the other end of this wire. However, I have a number of questions:
1) How can there be both high and low voltage wires connected to the same switch? Is there such thing as a switch with a built-in transformer?
2) How/why would the white/neutral wire be connected to the switch? Is this how you terminate a neutral wire when the load device doesn't have a neutral?
3) If the low voltage wire is connected to my furnace fan blower, how is power getting to the bathroom exhaust fan?
Any insight here would be greatly appreciated.